Outdoor Retailer Show 4: Next-Gen Avalanche Transceivers

Oct 1, 2009

Only a few companies make avalanche transceivers, and probably no one makes a bad one. But every few years there are some big advances, and this is one of those years: At least two significant new devices are generating interest here in Salt Lake City.

Basically, a transceiver continually emits a signal while you're traveling in avalanche terrain. If someone in the party is caught in an avalanche, the other members of the group turn their transceivers from "send" to "search." Now, instead of sending out a signal, they are receiving the signal from the buried person's device. But besides panic, concrete-heavy avalanche debris and the ticking clock to contend with, tracking an electromagnetic signal to its source takes considerable skill. The problems grow if there are multiple buried victims, and thus several signals all interfering with each other. Surviving an avalanche is a very iffy proposition anyway; the odds drop if a neophyte is conducting the search—ideally, everyone in the backcountry would have guide-level skills, but that, of course, is impossible.

As it happens, fatalities are on the rise in the United States (not to mention in other countries). For several years snowmobilers had overtaken other winter backcountry users in fatalities, but their numbers have gone down. The growth of snowshoeing, by the way, can be tracked, sadly, by their appearance and subsequent growth in the charts of those killed—the numbers can be seen here.

So what's new in transceivers? Basically, ease of use—which is the most important area for improvement. First, the devices have gotten better at helping a rescuer find several victims. Both the Ortovox S1 and the Barryvox Pulse clearly identify up to four buried victims. Both isolate the signals from the various sources so that the user can receive data on just one at a time. And both have mechanisms to allow a user to mark a victim as found, then move on to the next victim without turning off the first victim's transceiver. Another welcome feature is that the transceivers tell the searcher the quickest route to the victim. That seems obvious, but in the heat of the moment it's quite possible to follow the data trail away from the victim. Here's why. Essentially, all transceivers sense an electromagnetic field and point you along a curved "flux line" that leads to the victim. Because a flux line is roughly elliptical, though, you could easily follow it in the wrong direction. Sure, it'll curve back around to him eventually, but that's a waste of time.

This is all complex technology, and there are other important new features being introduced. And, to be fair, these capabilities aren't all unique to the Barryvox and Ortovox.

However, the Barryvox has two other features worthy of note that are unique. One is undeniably great and should eventually be adopted by other companies. The other feature is slightly creepy. The great feature is that Pulse transceivers that are in search mode communicate with each other. If three searchers are looking for three victims, the devices will help keep them from all accidentally focusing on the same person, ignoring the others. It's logical to think that this feature will eventually be adopted by other companies.

The chilling feature is that the Pulse has a very sensitive motion detector, activated after the transceiver has been relatively motionless for a period of time. It's sensitive enough to pick up a heart beat or respiration. A searcher looking at his own Pulse will know whether the victim he's looking for is still showing vital signs. If two victims are buried and only one appears to have a pulse or respiration, it will normally make sense to search for the victim with the better chance of survival first. It's probably good information to have; triage is a necessity in an emergency. But it's not an exaggeration to say that everyone I spoke with about the Barryvox Pulse thought it would lead to tough dilemmas—ones they weren't sure they'd ever want to face.

(Note: The Barryvox is sold by Mammut. The Ortovox photo is showing the device's ability to measure slope angle and temperature; neither is directly related to the main function.)—Jerry Beilinson

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